1 files changed, 156 insertions, 0 deletions
diff --git a/src/util/environ.c b/src/util/environ.c
new file mode 100644
index 0000000..4b6c59e
--- /dev/null
+++ b/src/util/environ.c
@@ -0,0 +1,156 @@
+ /*
+  * From: TCP Wrapper.
+  * 
+  * Many systems have putenv() but no setenv(). Other systems have setenv() but
+  * no putenv() (MIPS). Still other systems have neither (NeXT). This is a
+  * re-implementation that hopefully ends all problems.
+  * 
+  * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+  */
+#include "sys_defs.h"
+
+#ifdef MISSING_SETENV_PUTENV
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+extern char **environ;
+
+static int addenv(char *);		/* append entry to environment */
+static int allocated = 0;		/* environ is, or is not, allocated */
+
+#define DO_CLOBBER      1
+
+/* namelength - determine length of name in "name=whatever" */
+
+static ssize_t namelength(const char *name)
+{
+    char   *equal;
+
+    equal = strchr(name, '=');
+    return ((equal == 0) ? strlen(name) : (equal - name));
+}
+
+/* findenv - given name, locate name=value */
+
+static char **findenv(const char *name, ssize_t len)
+{
+    char  **envp;
+
+    for (envp = environ; envp && *envp; envp++)
+	if (strncmp(name, *envp, len) == 0 && (*envp)[len] == '=')
+	    return (envp);
+    return (0);
+}
+
+#if 0
+
+/* getenv - given name, locate value */
+
+char   *getenv(const char *name)
+{
+    ssize_t len = namelength(name);
+    char  **envp = findenv(name, len);
+
+    return (envp ? *envp + len + 1 : 0);
+}
+
+/* putenv - update or append environment (name,value) pair */
+
+int     putenv(const char *nameval)
+{
+    char   *equal = strchr(nameval, '=');
+    char   *value = (equal ? equal : "");
+
+    return (setenv(nameval, value, DO_CLOBBER));
+}
+
+/* unsetenv - remove variable from environment */
+
+void    unsetenv(const char *name)
+{
+    char  **envp;
+
+    while ((envp = findenv(name, namelength(name))) != 0)
+	while (envp[0] = envp[1])
+	    envp++;
+}
+
+#endif
+
+/* setenv - update or append environment (name,value) pair */
+
+int     setenv(const char *name, const char *value, int clobber)
+{
+    char   *destination;
+    char  **envp;
+    ssize_t l_name;			/* length of name part */
+    unsigned int l_nameval;		/* length of name=value */
+
+    /* Permit name= and =value. */
+
+    l_name = namelength(name);
+    envp = findenv(name, l_name);
+    if (envp != 0 && clobber == 0)
+	return (0);
+    if (*value == '=')
+	value++;
+    l_nameval = l_name + strlen(value) + 1;
+
+    /*
+     * Use available memory if the old value is long enough. Never free an
+     * old name=value entry because it may not be allocated.
+     */
+
+    destination = (envp != 0 && strlen(*envp) >= l_nameval) ?
+	*envp : malloc(l_nameval + 1);
+    if (destination == 0)
+	return (-1);
+    strncpy(destination, name, l_name);
+    destination[l_name] = '=';
+    strcpy(destination + l_name + 1, value);
+    return ((envp == 0) ? addenv(destination) : (*envp = destination, 0));
+}
+
+/* cmalloc - malloc and copy block of memory */
+
+static char *cmalloc(ssize_t new_len, char *old, ssize_t old_len)
+{
+    char   *new = malloc(new_len);
+
+    if (new != 0)
+	memcpy(new, old, old_len);
+    return (new);
+}
+
+/* addenv - append environment entry */
+
+static int addenv(char *nameval)
+{
+    char  **envp;
+    ssize_t n_used;			/* number of environment entries */
+    ssize_t l_used;			/* bytes used excl. terminator */
+    ssize_t l_need;			/* bytes needed incl. terminator */
+
+    for (envp = environ; envp && *envp; envp++)
+	 /* void */ ;
+    n_used = envp - environ;
+    l_used = n_used * sizeof(*envp);
+    l_need = l_used + 2 * sizeof(*envp);
+
+    envp = allocated ?
+	(char **) realloc((char *) environ, l_need) :
+	(char **) cmalloc(l_need, (char *) environ, l_used);
+    if (envp == 0) {
+	return (-1);
+    } else {
+	allocated = 1;
+	environ = envp;
+	environ[n_used++] = nameval;		/* add new entry */
+	environ[n_used] = 0;			/* terminate list */
+	return (0);
+    }
+}
+
+#endif